Abstract 3750
Background
Nasopharyngeal cancer (NPC) is characterized by a remarkable geographical variation and biologic diversity. Importantly, studies investigating mutation profiles of NPC in European populations are scarce.
Methods
We investigated the mutational profile of 127 NPC (89% EBV positive) in 93 Greek (GR) and 34 Romanian (RO) patients with locally advanced disease, treated with concomitant chemo-radiotherapy (CCRT) or induction chemotherapy (IC) followed by CCRT. In 19 tumors, dissected matched tumor/lymphocyte (T/L) pairs were compared. Mutation (amino acid changing, minor allele frequency
Results
We identified 1562 mutations in 101/129 tumors (94%). Mutations were mostly found in homologous recombination repair (HRR; 34%), chromatin remodelling (15%) and immune response related (IRR; 10%) genes. In the matched T/L samples, common mutations were identified in 10 cases only, the rest harbouring private mutations. Shared T/L mutations occurred at higher frequencies within the same tumor than T- and L-private mutations (p
Conclusions
Different genes and sets of genes are affected in stromal and tumor components of NPC, which is important for targeted treatment considerations. Ethnic differences in mutation profiles exist but do not seem to interfere with patient outcome, which seems adversely affected by the absence of EBV and by the presence of BRCA1 mutations.
Clinical trial identification
N/A
Legal entity responsible for the study
Hellenic Cooperative Oncology Group
Funding
Hellenic Cooperative Oncology Group
Disclosure
G. Fountzilas: Advisory Board: Astra Zeneca S.A. All other authors have declared no conflicts of interest.